Dialyzer assembling means



w. J. S MYTHE DIALYZER ASSEMBLING MEANS Feb. 4, 1969 Sheet Of2 Filed Oct. 2, 1967 INVENI'OR. WILLIAM J. SMYTHE ATTORNEY 1969 w. J. SMYTHE DIALYZER ASSEMBLING MEANS Sheet Filed Oct. 2, 1967 INVEN'I'OR.

WILLIAM J.SMYTHE BY jit j Ga A TTOR NE)" United States Patent 3,425,560 DIALYZER ASSEMBLING MEANS William J. Smythe, Rye, N.Y., assignor to Technician Corporation, Ardsley, N.Y., a corporation of New York Filed Oct. 2, 1967, Ser. No. 672,056 US. Cl. 210-232 Int. Cl. B01d 13/00 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Field of the invention This invention relates to the separation of liquids, and especially to systems for dialysis.

Prior art Apparatuses for the dialysis of a flowing stream of liquid samples are well known, and are shown, for example, in US. Patent No. Re. 24,736, issued to J. Isreeli on November 17, 1959. Essentially, such apparatus comprises a first block having a first channel formed therein, a second block having a second channel formed therein and mating with said first channel, and a membrane clamped between the blocks and separating said two channels. Substantial pressure is required to clamp the two blocks together to preclude leakage from the junction of a channel with the membrane. A flowing stream of sequential samples is transmitted through the first channel while a flowing stream of a recipient liquid is transmitted through the second channel. A portion of each sample migrates through the membrane from the sample stream into the recipient stream, To minimize the length of the leading portion of a succeeding sample which is contaminated by a preceding sample, it has been proposed to make this length of the channel as short as possible. Such an apparatus is shown in US. Patent No. 3,211,645, issued to A. Ferrari, on Oct. 12, 1965' and in US. Patent No. 3,333,706, issued to J. Isreeli on Aug. 1, 1967.

It is an object of this invention to provide such a dialyzer wherein the rather limited force provided by a female laboratory technician will be adequate to clamp the dialyzer together with leakage, and, furthermore, which will not damage the membrane adjacent the grooves.

SUMMARY OF THE INVENTION The principle of this invention is comprised in a dialyzer having a pair of blocks with mating channels in a U-shaped linear configuration, each leg of the U being equally spaced from and about a central force applying means to provide a balanced loading of the blocks; the mating surface on one of the blocks being relieved to provide a pair of ribs or lips bounding the contained channel, the surfaces of the lips being not so narrow as to pinch or extrude the membrane against the mating surface of the other block, nor so wide as to allow a deflection in either of the blocks to produce a leak, and generally of such relatively small area as to provide a relatively high pressure against the membrane for a relatively low clamping force.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features and advantages of this invention will become apparent from the following description thereof taken in conjunction with the accompanying drawing, in which:

FIGURE 1 is a side view in elevation of a dialyzer apparatus embodying this invention;

FIGURE 2 is a top view in plan of the dialyzer of FIGURE 1;

FIGURE 3 is an end view in elevation of the dialyzer of FIGURE 1, including a schematic showing of a flow test manifold;

FIGURE 4 is plan view of the grooved surface of the top block of the dialyzer of FIGURE 1;

FIGURE 5 is a plan view of the grooved surface of the bottom block of the dialyzer of FIGURE 1;

FIGURE 6 is a view in cross-section taken along the plane suggested by line 6-6 in FIGURE 2; and

FIGURE 7 is a view in cross-section taken along the plane suggested by line 77 in FIGURE 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The dialyzer assembly shown in FIGURE 1 includes a first, and customarily, but not necessarily, upper block 10, and a second, and customarily, but not necessarily, lower block 12. Each block has a respective plurality of bores 14, 16 therethrough disposed along the longitudinal vertical midline plane. One bore 14 is coaxial with a respective bore 16 to pass therethrough a clamping screw assembly 18. Each assembly includes a clamping screw 20, having a head 22 and a washer 24 screwed thereto, a cross-pin 26 passing through the head and the screw, and a nut 28. The blocks may be a methacrylate plastic while the screw assembly may be stainless steel. A membrane 30, such as a sheet of cellophane, is clamped between the two blocks. Advantageously, plurality of holes, not shown, is cut through the membrane to mate with the bores 14 and 16. The membrane is normally made wet before it is clamped between the blocks, and may be supported, wrinkle free, on a hoop 32 as it is mounted between the blocks. The hoop may be of substantially oval annular shape, with a V-shaped indentation 34 in the outer surface, as best seen in FIGURES 6 and 7. The membrane may be laid on and around the hoop, and held in place by an elastic band 36 disposed in the indentation 34. The hoop may be split, as at 38, so that while the dialyzer is connected in an analytic system, the elastic band may be released from the hoop and the hoop may be spread open at the split and slid away from the dialyzer.

If desired, a plurality of locating pins 40 and mating locating holes 42, may be provided on the respective mating faces 44 and 46 of the blocks, and the membrane may have suitable holes, not shown, out therein to clear these plIlS.

A U-shaped channel 48 is formed into the surface 44 of the block 10, and a mating U-shaped channel 50 is formed into the surface 52 of the block 12. The channels are symmetric about the longitudinal midline vertical plane of the blocks through which the clamping screws 22 pass. The channel 50 comprises a groove which is semicircular in cross-section formed into the flat surface 46. The channel 48 comprises a groove which is semi-circular in cross-section formed into a flat plane. However, this plane is relieved to provide two lips 44A and 44B bounding and forming part of the channel 48, and upstanding from the relieved surface 44C. Thus, the membrane is actually clamped between the plateaus of the two lips 44A and 44B and the opposed portions of the surface 46. The width of the plateaus of the lips should be made nar- Patented Feb. 4, 1969 row enough to provide a relatively high pressure on the membrane for a relatively low clamping force applied to the clamping screws and, thereby, to the blocks. However, this width should not be so narrow as to pinch or extrude the membrane under this pressure. Moreover, as described above, the grooves should be equally spaced on both sides of the longitudinal midline vertical plane, so that the torque on each plateau is identical to the torque on the corresponding plateau on the other side of the plane. Finally, the width of the plateaus should not be so wide as to permit a deflection therein which would permit leakage.

I have found that in a unit having a spacing between center lines of the two legs of the U-shaped channel of 0.5 inch, a groove having a diameter of .063 inch with plateaus having a width of .03 inch, and a height of .0315 inch, on a wet membrane, clamped together by UNC screws on 1.67 inch spacing at about 8 inch-pounds is satisfactory. Should some warpage develop in the blocks, a torque of inch-pounds becomes satisfactory.

The ends of the channels 48 and 50 terminate in suitable inlet and outlet tapered bores 60. These bores are drilled at an angle to the channels to allow clearance for the respective nipple assemblies 62, which are fitted into respective counterbores 64. Each assembly 62 includes a sleeve 66, an adaptor 68, a sleeve 70 and a nipple 72.

As shown in FIGURE 3, the dialyzer assembly may readily be tested for leakage in simulated operational cicumstances. The inlet assembly 62A of the channel 48 is coupled through the pump tubes of a suitable peristaltic type pump 74 to a source of dyed water 76 and a source of gas 78, while the output assembly 62B is coupled through a coil 80 to waste. The inlet assembly 62C is similarly coupled through the pump tubes to a source of dyed water 82 and a source of gas 81, while the output assembly 62D is coupled through a coil 80 to waste.

What is claimed is:

1. A dialyzer assembly, for use with a membrane, comprising:

a first block and a second block each having a respec-. tive confronting surface for receiving the membrane therebetween;

a first channel formed into said surface of said first block and a second channel, mating with said first channel, formed into said surface of said second block;

said surface of said first block being relieved except adjacent said first channel to provide two lips, one on each side of and forming said first channel, said two lips being adapted to abut the membrane against the surface of the second block.

2. A dialyzer assembly according to claim 1:

further including a hOOp for supporting the membrane while it is being clamped between said blocks, said hoop normally encircling said blocks,

said hoop having a split therein whereby said hoop may be opened into a C-shape to clear said blocks.

3. A dialyzer assembly according to claim 1, wherein:

said first and second channels are respectively U-shaped longitudinally, each having two lips;

further including means for clamping said two blocks together, disposed centrally between the two legs of said U-shaped channels.

4. A dialyzer assembly according to claim 3:

wherein said clamping means comprises a plurality of spaced apart clamping screws disposed along the longitudinal midline plane between the two legs of said U-shaped channels.

5. A dialyzer assembly according to claim 1:

wherein each of said lips has a flat plateau for abuting the membrane.

6. A dialyzer assembly according to claim 5:

wherein the width of each fiat to the spacing between flats is of the order of 3 to 6.

7. A dialyzer according to claim 6:

wherein the spacing between centers of the legs of the channels to the width of each flat is of the order of to 3.

References Cited UNITED STATES PATENTS R 24,736 11/1959 Isreeli 210321 3,333,706 8/1967 Isreeli 210321 3,341,022 9/1967 ISreeli 2l0321 X REUBEN FRIEDMAN, Primary Examiner.

F. A. SPEAR, 1a., Assistant Examiner.

U .8. Cl. X.R. 

